﻿/*
 * SonarLint for Visual Studio
 * Copyright (C) 2016-2020 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;

namespace SonarLint.VisualStudio.Integration.Vsix
{
    public static class TcpUtil
    {
        public static int FindFreePort(int startPort)
        {
            IPGlobalProperties ipGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();
            TcpConnectionInformation[] tcpConnInfoArray = ipGlobalProperties.GetActiveTcpConnections();
            IPEndPoint[] ipEndPoint = ipGlobalProperties.GetActiveTcpListeners();

            List<int> usedPorts = ipEndPoint.Select(x => x.Port)
                .Concat(tcpConnInfoArray.Select(x => x.LocalEndPoint.Port)).ToList();

            for (int i = startPort; i < UInt16.MaxValue; i++)
            {
                if (!usedPorts.Contains(i))
                {
                    return i;
                }
            }
            throw new InvalidOperationException("Could not find any free TCP port over port " + startPort);
        }
    }
}
